What is an adjective clause introduced by?

• A. Because, since, or unless.
• B. That, where, or when.
• C. Who, which, or that.
• D. If, unless, or though.

Answer: (C)

Adjective clauses describe a noun and are introduced by relative words that connect the clause to that noun. The most common starters are who, which, and that, because they refer back to people or things and let the clause tell us more about the noun. For example: The student who won the prize spoke calmly. Here the clause who won the prize describes student. The other starters belong to different kinds of clauses: because, since, or unless begin adverbial clauses that explain reasons or conditions rather than modify a noun; if, unless, or though also introduce adverbial clauses; where and when can introduce relative clauses too, but the principal relatives used to start an adjective clause are who, which, or that.